Search Previous Year Questions

The correct answer is Absence of cell wall

Explanation:

• Kingdom Animalia is characterized by organisms that have cells without cell walls.
• Unlike plants, fungi, and some protists, animal cells do not have a rigid cell wall; instead, they have a flexible cell membrane.
• This allows for a greater range of motion and diverse forms of movement, which are characteristic of animals.
• Additionally, animals are typically heterotrophic, meaning they obtain their nutrition by consuming other organisms.

The correct answer is the Central nervous system is dorsal

Explanation:

The features of non-chordates among the given statements are:

• The central nervous system is ventral.
• Gill slits are absent.
• Heart is dorsal

Comparison of Chordates and Non-chordates:- 

The correct answer is Anacardiacea

Explanation:

• Mango (Anacardiaceae): Mango belongs to the family Anacardiaceae, which is a family of flowering plants that includes numerous edible and inedible fruits.
• Wheat (Poaceae): Wheat belongs to the family Poaceae, which is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses.
• Housefly (Muscidae): The housefly belongs to the family Muscidae, which comprises a large group of flies known for their significance in medical and veterinary fields.
• Man (Hominidae): Humans belong to the family Hominidae, commonly known as great apes, which include orangutans, gorillas, chimpanzees, and humans.

The correct answer is Encystation

Explanation:

• In unfavorable conditions, an amoeba forms a three-layered hard covering around itself through a process known as encystation.
• This protective cyst allows the amoeba to survive harsh environmental conditions such as extreme temperatures, desiccation, or lack of food.
• When conditions become favorable again, the amoeba can exit the cyst and resume its normal activities.

The correct answer is Pneumatophores

Explanation:

• Pneumatophores are specialized roots that grow vertically out of the ground in swampy or waterlogged areas.
• These roots help in gas exchange by allowing oxygen to reach the submerged root systems.
• Plants that commonly have pneumatophores include mangroves and other species adapted to grow in marshy environments.
• Pneumatophores are found in Rhizophora. Pneumatophores are the respiratory roots found in plants growing in salty marshes.

Other Options:

• Taproot is a dominant root from which other roots sprout laterally and grows faster than the branch roots. Example: Carrot, Radishes and Beetroot.
• Fibrous roots have very fine branches of approximately the same length. Example: onions, tomatoes, corn, rice and wheat.
• Stilt roots: In Maize and Sugarcane, roots arise from the first few nodes of the stem and penetrate obliquely down into the soil and giving support to the plant. They are called Stilt roots. Stilt roots are the adventitious roots that help in supporting the plant body. It is also known as the support roots. They develop from the basal nodes of the main stem and grow obliquely

The correct answer is (A) - regulator (B) - conformer  (C) - partial regulator

Explanation: 

• Regulate:  Some organisms are able to maintain homeostasis by physiological (sometimes behavioural also) means which ensures constant body temperature, constant osmotic concentration, etc.
• All birds and mammals, and a very few lower vertebrate and invertebrate species are capable of such regulation (thermoregulation and osmoregulation)..
• Evolutionary biologists believe that the 'success' of mammals is largely due to their ability to maintain a constant body temperature and thrive whether they live in Antarctica or in the Sahara desert.
• Plants, on the other hand, do not have such mechanisms to maintain internal temperatures.
• Conform: 99 percent of animals and nearly all plants cannot maintain a constant internal environment. Their body temperature changes with the ambient temperature. In aquatic animals/the osmotic concentration of the body fluids changes with that of the ambient air, water osmotic concentration. These animals and plants are simply conformers.

Fig: Diagrammatic representation of organism response

The correct answer is Allen's rule

Explanation:

• Allen's Rule is a biological principle that states that endothermic (warm-blooded) animals adapted to cold climates have shorter appendages (such as limbs, ears, and tails) compared to those adapted to warmer climates. This is an adaptation to minimize heat loss.
• The rule is named after the American zoologist Joel Asaph Allen, who first formulated it in 1877.
• According to Allen's Rule, animals in colder climates will have shorter extremities to reduce surface area and thereby conserve body heat. Conversely, animals in warmer climates will have longer extremities to help dissipate body heat.

The correct answer is Catabolism

Explanation:

• Dead plant remains such as leaves, bark, flowers and dead remains of animals, including fecal matter, constitute detritus, which is the raw material for decomposition.
• The important steps in the process of decomposition are fragmentation, leaching, catabolism, humification and mineralisation.
• Fragmentation: This is the initial stage where organic waste and dead matter are broken down by detritivores.
• Leaching: By the process of leaching, water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts
• Catabolism: Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism.
• Humification: Humification leads to the accumulation of a dark coloured amorphous substance called humus that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate. Being colloidal in nature it serves as a reservoir of nutrients
• Mineralisation: The humus is further degraded by some microbes and release of inorganic nutrients occur by the process known as mineralisation

The correct answer is succinyl-CoA to succinic acid

Concept:

• The Krebs cycle, also known as the citric acid cycle or TCA (tricarboxylic acid) cycle, is a series of enzymatic reactions in the mitochondria that generates ATP through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins.
• One molecule of GTP (or ATP in certain cells) is produced directly in the Krebs cycle.
• GTP synthesis involves substrate-level phosphorylation, a process where a phosphate group is directly transferred from a substrate to ADP or GDP.
• Succinyl-CoA to succinic acid: This step involves the conversion of succinyl-CoA to succinate. The enzyme succinyl-CoA synthetase catalyzes a substrate-level phosphorylation reaction, resulting in the formation of GTP (or ATP) from GDP and Pi. This is the only step in the Krebs cycle where GTP is directly synthesized.

The correct answer is A: Troponin, B: F - actin,  C: Tropomyosin

Explanation:

• Each actin (thin) filament is made of two ‘F’ (filamentous) actions helically wound to each other.
• Each ‘F’ actin is a polymer of monomeric ‘G’ (Globular) actins.
• Two filaments of another protein, tropomyosin also run close to the ‘F’ actins throughout its length.
• A complex protein Troponin is distributed at regular intervals on the tropomyosin.
• In the resting state a subunit of troponin masks the active binding sites for myosin on the actin filaments

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